Historic production from the 1880s to the 1950s
yielded an estimated 144,000 ounces of gold
While work on the nearby Broadway gold mine started over a century ago, the Madison project has never been fully exploited or explored.
There was underground mining at the Broadway mine from the 1880s to the 1950s. During that time, the mine was developed to a vertical depth of ~229 meters and there was a total of ~610 meters of lateral development. Production yielded an estimated 144,000 ounces of gold (450,000 tons averaging 0.32 ounces per ton gold).
Four companies operated the Broadway mine and Madison property from the 1980s through to the mid-1990s. The first mention of a potential deep porphyry target was in 1986 and it was postulated by another previous property owner again in 1992, however operations continued to focus efforts on the shallower, high-grade gold mineralization. A total of 55 core holes (6,450 meters) and 32 RC holes (3,710 meters) were drilled during this timeframe.
Madison was acquired in 2005 by Coronado – the company from which Broadway would eventually acquire the Madison project in October 2016. Before putting the property on care and maintenance in 2012, Coronado is estimated to have spent US$10-million and CAD$3-million on drill programs (core and underground core holes) as well as underground development and underground trial mining (bulk sampling) to the 600 level. Oxide gold, massive sulfide gold and copper mineralization was stockpiled for subsequent mill shipment. A crushing plant, certified weight scale and sufficient power exist on the current property.
In 2008, the first oxide gold averaging 19 g/t was shipped to Barrick Gold’s nearby Golden Sunlight Mine in Whitehall, Montana. Copper was also shipped to China this same year.
The first sulfide gold averaging 20 g/t was shipped to Kinross Gold’s Republic Mine in Republic, Washington in 2009.
Based on data from 12 shipments, the gold recovery had an overall average of 83%.
In total, approximately 20,000 tons (14,597 tons of gold skarn, 5,208 tons of copper skarn) was shipped as bulk samples during underground development and trial mining, with recoveries of 7,570 ounces of gold and 3,020,000 pounds of copper.